Working fluid for refrigeration



Nov. 12, 1929. A. A. KUCHER 1,735,170

WORKING FLUID FOR REFRIGERATION Filed Aug. 11 1926 & 09:0 00% 000- 0000@000 0000 0099 if @990- @009 Q c J g Q-23 24 K C l/ v Q 29 II I a W i E32 /,2z

Andrew A. Kucher WITNESSES: l lNVENTOR &\\ Y

W i /0 Y "I, GIIU5.M

ATTORNEY Patented Nov. 12, 1929 UNITED STATES PATENT: OFFICE ANDREW A.IK'UCHER, OF CHESTER, PENNSYLVANIA,

ASSIGNOR TO WESTINGHOUSE WORKING FLUID FOR REFRIGERATION Applicationfiled August 11, 1926. Serial No. 128,656.

My invention relates to the art of refrigeration, particularly aspracticed by the so-called compression process, and itahas for an objectto provide an improved working fluid for use in processes of thecharacter designated which shall have the required physicalcharacteristics and which shall possess both refrigerating andlubricating qualities.

It has heretofore been generally proposed to employ in compressionrefrigerators .a lubricant which is immiscible with the refrigerant,that is, a refrigerant and a lubricant which separate readily bygravity. Many liquids possessing to a greater or lesser extent this proerty have been used, generally with incomp etc success, since no combination of a refrigerant and a lubricant has been found in which theliquids do not mingle to some slight extent when brought together underthe conditions of agitation obtaining in a compression refrigerator.Mechanical separators of various types have been employed with some ofthese machines in order to facilitate the separation of the refrigerantand the lubricant. This expedient has improved the operation but has notresulted in accomplishing a complete separation of the refrigerantfromthe lubricant. In machines employing such refrigerants andlubricants, continued operation generally results in some of thelubricant being dissolved in the refrigerant and possibly some of therefrigerant in the lubricant. However, the percentage of refrigerantdissolved in the lubricant is so small that the solution thus producedhas substantially no refrigerating qualities while its effectiveness asa lubricant is materially lessened. On the other hand, where thelubricant is dissolved in the refrigerant,

the effectiveness of the refrigerating fluid is impaired and thepercentage of lubricant contained therein is so small as to make itentirely unsuited for lubricating purposes. In such machines, therefore,there results, after a.

continued period of operation, a lubricant whose lubricating. qualitieshave been impaired by its solution with some refrigerant and arefrigerant whose refrigerating qualities have been impaired by itssolution with some lubricant.

In the present invention, I have departed radically from previousattempts to use refrigerants and lubricants which are immiscible and Ihave evolved a single liquid, which I term a working fluid, whichworkin'g fluid is capable of not only producing the requiredrefrigerating effect but of refrigerating machine as well. This workingfluid consists of a refrigerant and a lubricant which readily mix insubstantially all proportions, one with the other, to form a physicalsolution or a homogeneous liquid of a character that its constituentsare soluble in each other and not separable mechanically orgravitationally. By using such a workiplg fluid, I am able to overcomecompletely t e perienced in the operation of compression refrigerators.

In obtaining a workin fluid of this character, a wide range of rerigerants and lubricants may be employed. I have found by experimentthat castor oil serves best as a lubricant and that it forms ahomogeneous solution in substantially all proportions with sulphurdioxide. However, I may employ as equivalents of sul hur dioxide eitherethyl chloride or methyl c loride. All of the foregoing refrigerants arewell known and widely used. I have further found that castor 011 forms aphysical solution with any of these refrigerants in substantially allprop0rtions.-

The amount of castor oil employed in (proportion to the amount'of refrierant epends upon the type of machine w erein it is utilized andespecially upon the type of compressor .or pump emp oyed. I have found,

that, with some machines, very satisfactory results can beobtained busing about castor oil and liquid re rigerant by volufne.

Ihave found that under severe centrifugal tests, this admixture ofcastor oil and sulphur dioxide, exhibits no tendency to separate intoits constituents and hence may be said to constitute a true physicalsolution. This characteristic of my workin fluid I have defined by theterm mechanics. yinse arable. The refrigerant may be separated rom thelllbl'llubricating the cant, however, by a distillation process. Asstated heretofore, such a mixture is homogeneous, by which is meantthata body of such liquid possesses the same physical characteristicsand properties throughout all portions.

It is generally recognized that sulphur dioxide exerts a corrosiveaction upon some metals. However, I have found that by mixing it withcastor oil, this corrosive action is not found and hence my workingfluid may be said to be non-corrosive, a highly desirable quality. Inthe drawing accompanying this application, I show one form ofcompression refrigerator in which a working fluid such as heretoforedescribed may be employed. This is a type of machine which is similar tothat shown and described in a co-pending application of mine, Serial170.550. 145, filed April 7, 1922, and entitled Refrigeratm. Thismachine comprises a chamber 10 within which is disposed an electricmotor 11 connected through a shaft 12 to a compressor 13. The compressorshown is of the rotary, two-stage type although it is to be understoodthat my working fluid may also be readily employed with compressors ofthe reciprocating type. The shaft 12 is carried in upper and lowerbearings 14 and 15 and an arrester 16 is secured to the shaft within thehousing of the motor to catch liquid draining downwardly along the shaftfrom the compressor.

. Disposed within the chamber 10, are a plurality of condensing coils 17having an inlet 18 for the admission of cooling water and an outlet, notshown. The compressor 13 discharges through the port 19 into thecondensing chamber 10 and the condensed liquid is conveyed to a coolingelement or evaporator 21 by a conduit 22. A valve 23 operated by a float24 is provided for controlling the flow of liquid through the conduit22. p

A body of my novel working fluid is provided in a liquid state in boththe condensing chamber 10 and the evaporator 21. The levels of these twobodies of liquid are, during normal operation, inch as indicated at 25and 26 respectively. Provided within the evaporator 21 is a vaporconduit 27 which connects with a vapor conduit 28 communicating with theinlet port 29 of the compressor 13. The vapor conduit 27 is so formed asto reverse the flow of the vapor. It has its entrant portion 31 disposedwell above the normal operatinglevel of the liquid in the evaporator andhas its lower-most portion disposed well below the normal operatinglevel of the liquid within the evaporator. Provided in this lower-mostportion is a small aperture or hole 32 for entraining liquid-in thevapor conduit 27. A. drain port 33 opens into the vapor conduit 28 topermit any liquid which may accumulate in the lower portion of thehousing of the motor, to return to the compressor.

The operation of amachine such as described is as follows: Thecondensing chamber 10 and the evaporating chamber 21 are filledapproximately to the levels indicatedv in the drawing at 25 and 26, withmy novel working fluid. Prior to starting the motor a quantity of theliquid working fluid fills the vapor suction tube 27 to the level of theliquid in the evaporator 21. The first rotations of the compressor 13draw this liquid into the compressor so that a thoroughpriming of themoving parts is obtained during the initial operation thereof. Thepriming liquid not only lubricates the frictionally engaging surfacesbut seals the Working chambers of the pump against vapor leakage. As therotation of the pump continues, vapors from the evaporator 21 are drawnthrough the conduits 27 and 28 to the suction port 29 of the compressor13 from whence they are discharged into the condensing chamber 10 at anincreased pressure. A fine stream or spray of the liquid in theevaporator 21 enters the vapor conduit 27 through the aperture 32 and 1scommingled with the vapors flowing through the conduits 27 and 28'to thecompressor. This commingled liquid serves to seal and lubricate the pumpin passing therethrough and is supplied continuously as long as thecompressor is in operation. When a predetermined cooling action hasresulted from the operation of the machine, automatic mechanism (notshown) cuts off the current to the motor and thus stops the action ofthey compressor. During the period of rest which follows, some of theliquid in the evaporator 21 fills the lower portion of the vapor conduit27, placing the machine in readiness for starting again.

The lubrication of the shaft bearings 14 and 15 is accomplished from theliquid delivered to the compressor. Some of this liquid seeps downthrough the upper bearing 14 and, in View of the fact that this liquidhas lubricating qualities in addition to its refrigerating ualities, itlubricates the bearing in passing t erethrough. The liquid drains fromthe lower end of the bearing into the arrester 16 from whence it isthrown by centrifugal force to the side walls of the housing of themotor and collects in the bottom thereof. A shallow pool of liquid isconstantly maintained therein for lubricating the lower bearing 15,

the excess being carried away through the drain port 33 into the vaporconduit 28 wherein it commingles with the refrigerant vapor and, incombination with the liquid entrained in the evaporator, seals andlubricates the compressor in passing therethrough.

l/Vhile I have shown my invention in but one form, it will be obvious tothose skilledin the art that it is not so limited, but is susceptible ofvarious changes and modifications,

Without departing from the spirit thereof, and I desire, therefore, thatonly such limitations shall be placed thereupon as are 1mposed by theprior art or as are specifically set forth in the appended claims.

What I claim is 1. A working fluid for a refrigerating machine whichconsists of castor oil and a refrigeratingfluid which forms with castoroil a homogeneous mixture or physical solution in substantially allproportions.

2. A working fluidfor a refrigerting machine which consists of castoroil and sulphur dioxide forming with the castor oil a physical solutionor homogeneous mixture in substantially all proportions.

3. A working fluid for a refrigerating machine which consists of sulphurdioxide and a lubricant which forms therewith a mechanically inseparablehomogeneous mixture in substantially all proportions.

4. A working fluid for a refrigerating machine which consists at leastin part of castor oil, and sulphur dioxide. 5. A working fluid for arefrigerating machine which consists of sulphur dioxide and castor oil,the volume of liquid sulphur dioxidf predominating over the volume ofcastor o1 6. A working fluid for a refrigerating machine which consistsof at least ten per cent castor oil by volume and a refrigerant whichforms therewith a mechanically inseparable homogeneous mixture insubstantially all proportions.

7 A working liquid for a refrigerating machine which consists of sulphurdioxide and castor oil, the castor oil comprising at least ten per centof the volume of the working liquid.

8. A working'fluid for a refrigerating machine which consists ofsubstantially castor oil and liquid sulphur dioxide by volume 9.refrigerating machine which consists in alternately compressing,condensing and expanding a refrigerant medium having intimately andhomogeneously mixed therewith particles of castor oil.

10. The method of lubricating a closedcycle refrigerating machine whichconsists in alternately compressing, condensing and expanding sulphurdioxide having intimately and homogeneously mixed therewith particlesof'a lubricating medium.

11. The method oflubricating a closedcycle refrigerating machine whichconsists in alternately compressing, condensing and expanding sulphurdioxide having intimately mixed therewith particles of castoroil.

In testimony whereof, I have hereunto subscribed my name this twelfthday of July,

ANDREW A. KUCHER.

. The method of lubricating a closed-cycle

